Primary succession

It is a sequential development of communities in a bare or soil -less area. Examples of of such areas include the rock or mud exposed by a retreating glacier, cooled volcanic lava or surface- minded areas from which all top soil has been removed. On such surface- minded areas from which all top soil been removed. On such barren surface, primary succession from bare rock to a mature forest may take hundreds to thousands of years.

Secondary succession

It is a sequential development of communities in an area where the natural vegetation has been removed or destroyed but the soil or bottom sediment is not destroyed. Examples of areas that can undergo secondary succession include abandoned farmlands burned forests, land stripped of vegetation for surface mining heavily polluted streams, and land that has been flooded naturally. Since some soil sediment is present, new vegetation can usually sprout within only few weeks.

Autogenic succession

It is caused by interactions of the organisms itself. After beginning of succession, vegetation, as a result of its reactions with the environment modifies its own environment and thus replaces itself by new communities.

Autotrophic succession

It is under it, food web based depended on photosynthetic organisms. There autotrophic organisms as green plants and trees dominate. Mostly it starts in inorganic environment ,energy flow and maintained indefinitely followed by general increase in the organic.

Allogenic succession

Sometimes, replacement of existing communities influenced by extrinsic or external factors and not by existing vegetation itself.

Heterotrophic succession

It depends on preformed organic matter for the food web based. In it, heterotrophs dominate such as bacteria, fungi and other consumers. Likewise, this succession starts in a organic environment followed by progressive decline of the energy contents of ecosystem.